The control of bleeding is essential and critical in surgical procedures to minimize blood loss, to reduce post-surgical complications, and to shorten the duration of the surgery in the operating room. Due to its biodegradability and its bactericidal and hemostatic properties, cellulose that has been oxidized to contain carboxylic acid moieties, hereinafter referred to as carboxylic-oxidized cellulose, has long been used as a topical hemostatic wound dressing in a variety of surgical procedures, including neurosurgery, abdominal surgery, cardiovascular surgery, thoracic surgery, head and neck surgery, pelvic surgery and skin and subcutaneous tissue procedures.
Currently utilized hemostatic wound dressings include knitted or non-woven fabrics comprising carboxylic-oxidized cellulose. Currently utilized oxidized regenerated cellulose (ORC) is carboxylic-oxidized cellulose comprising reactive carboxylic acid groups and which has been treated to increase homogeneity of the cellulose fiber. Examples of such hemostatic wound dressings commercially available include Surgicel® absorbable hemostat; Surgicel Nu-Knit® absorbable hemostat; and Surgicel® Fibrillar absorbable hemostat; all available from Johnson & Johnson Wound Management Worldwide, a division of Ethicon, Inc., Somerville, N.J., a Johnson & Johnson Company. Other examples of commercial absorbable hemostats containing carboxylic-oxidized cellulose include Oxycel® absorbable cellulose surgical dressing from Becton Dickinson and Company, Morris Plains, N.J. The oxidized cellulose hemostats noted above are knitted fabrics having a porous structure effective for providing hemostasis. They exhibit good tensile and compressive strength and are flexible such that a physician can effectively place the hemostat in position and maneuver the dressing during the particular procedure being performed.
Published U.S. Patent application No. 2006/051398 describes the fully amorphous copolymers of poly(ethylene diglycolate) (PEDG) and glycolide for use as films in adhesion prevention formulations. The application is silent with the regard of using this film in combination with hemostasis products to achieve enhanced hemostasis performance.
U.S. Pat. No. 6,500,777 describes a method for forming an ORC (oxidized regenerated cellulose) multilayered film for use as an adhesion prevention barrier comprising a cellulose film with cellulose fabric (sandwiched between films) followed by oxidation of multi-layered film. The film is placed on both sides of ORC Fabric. The cellulose film, subject to further oxidization, is not of a continuous, non-porous polymer-based film. In addition, the intended use of the device is for adhesion prevention, and is silent for use in hemostasis.
Published US Patent application No. 2008/0254091 describes a multi-layered adhesion prevention barrier comprising a nanofibrous electrospun layer coated on both side with hydrophilic non-synthetic, bio-originated polymer film. This device is intended for adhesion prevention. The reference is silent about the hemostasis use which does address the specific sidedness of the polymeric film.
U.S. Pat. No. 7,238,850 describes a multi-layered multi-function hemostasis tool for stopping bleeding by absorbing blood from the wound, which includes a lamination comprising a water-permeable inner material on the wound side, a water-impermeable outer material on the side departing from the wound side, a pulp-cotton laminated body between the inner and outer materials, a crust between the pulp-cotton laminated body and the water-impermeable outer material for diffusing the blood that has passed through the water-permeable inner material and the pulp-cotton laminated body, and a polymer for absorbing the blood diffused by the crust. However, the reference is silent on having a top, non-porous, continuous film layer made from amorphous or low crystallinity absorbable polymers.
Published US Patent Application No. 2005/0113849 describes a prosthetic repair device comprising a non-absorbable material, a first absorbable material having a first absorption rate and a second absorbable material having a faster absorption rate than the first absorption rate. Alternatively, the non-absorbable material is encapsulated with a first absorbable component having a first absorption rate. The device, having a non-absorbable component, is intended for hernia repair procedures and is silent for the use as a hemostatic device.
Published US Patent Application No. 2006/0257457 is directed to a method of making a reinforced absorbable multilayered hemostatic wound dressing comprising a first absorbable non-woven fabric, a second absorbable woven or knitted fabric, including also a thrombin and/or fibrinogen as a hemostatic agents. The reference is silent on having a non-porous, continuous film component.
U.S. Pat. No. 7,279,177 B2 assigned to Ethicon is directed to a hemostatic wound dressing that utilizes a fibrous, fabric substrate made from carboxylic-oxidized cellulose and containing a first surface and a second surface opposing the first surface, the fabric having flexibility, strength and porosity effective for use as a hemostat; and further having a porous, polymeric matrix substantially homogeneously distributed on the first and second surfaces and through the fabric, the porous, polymeric matrix being made of a biocompatible, water-soluble or water-swellable cellulose polymer, wherein prior to distribution of the polymeric matrix on and through the fabric, the fabric contains about 3 percent by weight or more of water-soluble oligosaccharides. The reference is silent on having a non-porous, continuous film.
Decreasing the time to achieve hemostasis has great clinical significance—to save blood loss and speed up the procedure. The majority of current products on the market in case of mild to moderate bleeding achieve hemostasis in a time frame from about 4 to 8 minutes. In addition, many products do not have ideal handling characteristics as they wrinkle and fold during surgical procedures especially in the presence of blood or other fluids. A medical needs remains for hemostatic devices that have better mechanical properties, particularly for use in laparoscopic procedures. Finally, some products when used in multiple layers or those in particulate form may disintegrate or their parts may migrate during the application process. There is a clear medical need to achieve faster hemostasis to reduce blood loss during surgery as well as a desire to provide improved handling performance and an improved ability to stay in place after application.